Do Mothers Trigger Juvenile Diabetes?

In the early stages, many diabetics show no symptoms of the disease itself and its complications. Thus screening is an important means of detecting disease. In fact, the concentration of blood antibodies against the body’s own insulin-producing cells is a strong indicator of the age at which diabetes develops. Whereas these antibodies have always been thought to be a symptom of disease rather than a cause, scientists at the University of Pennsylvania School of Medicine are now challenging that theory.

Using mouse models, Ali Naji and colleagues suggest that antibodies from the mother may be causing Type 1, or juvenile diabetes in the offspring (Nature Medicine, Vol. 8, No. 4, 01 Apr 02, p. 399). They have 3 lines of evidence to support this: mothers lacking B-cells that are able to produce antibodies and mothers genetically manipulated not to be able to produce insulin-specific antibodies, but still possessing B-cells, both yield fewer offspring with diabetes than normal mice. And embryos implanted into foster mothers that are genetically not prone to developing diabetes are less likely to develop the disease than those implanted into normal mouse mothers.

The scientists conclude that antibodies may be transmitted from mothers to infants; in those offspring that are susceptible, this transfer may trigger diabetes. Matthias von Herrath of the La Jolla Institute for Allergy & Immunology explains why the findings are so controversial in an accompanying News & Views article (p. 331).